Packing units for heat exchangers operating at extremely low temperatures



Dec. 8, 1964 w. LEHMER ETAL 3,159,910

PACKING UNITS F OR HEAT EXCHANGERS OPERATING AT EXTREMELY LOW TEMPERATURES Filed Dec. 10, 1958 INVENTORJ' WILHELM LEHMER ALBERT REIN JOSEF WEISHAUPT i f M ATTORNEYS United States Patent Office Patented Dec. 8, 1964 3,159,910 PACKING UNITS FOR HEAT EXCHANGERS OPER- ATING AT EXTREMELY LOW TEMPERATURES Wilhelm Lehmer, Munich, Albert Rein, Augsburg-Westheim, and Josef Weishaupt, Pullach, Germany, assignors to Gesellschaft fur Lindes Eismaschinen Alrtiengesellschaft, Munich, Germany, a company of Germany Filed Dec. 10, 1958, S'er. No. 779,484 Claims priority, application Germany Dec. 12, 1957 1 Claim. (Cl. 29-417) The invention concerns packing units of a special form, particularly for heatand cold exchangers, With substantially convex limiting surfaces, whose characteristic feature consists in that they have a tetrahedral, octahedral or pillow-like form, deviating from the known spherical form, by which a larger surface can be obtained, with uniform filling, than by the spherical form. This form has proved particularly successful for regenerators in refrigerating plants, for example, in gas decomposing plants, because these packings have a better packing than the spheres and, on the other hand, permit an optimum heat transfer. In addition, they have the further advantage that they are easy to manufacture, which can be eiiected in a very simple way, viz, the various pieces of the cylindrical starting material can be separated into said pieces by squeezing (or pinching) off successive portions of the cylinder. In severing such portions, the successive compression zones may lie in the same plane-in which event pillow-like pieces are squeezed oif--or the compression zones may if desired be turned with respect to each other alternately by 90, in which case the tetrahedral piece of FIG. 2 is formed.

It heretofore had been proposed to produce the packing units as hollow bodies from aluminum plate.

The present development of the inventive idea concerns mainly the problem of designing packing units for heat exchangers and regenerators, respectively, to be operated at relatively low temperatures, and particularly apparatus which is to be operated at temperatures between the liquefaction temperatures of nitrogen and hydrogen. In particular, it is intended to use the packing units for cooling and simultaneously for purifying hydrogen gas in regenerators.

According to the invention the heat-exchanger packing units of a tetrahedral-, octahedral or pillow-like form, having substantially only convex surfaces but deviating from the spherical form, are designed as solid packing units of ceramic material or heavy metal. Preferably the packing units according to the invention are made of lead.

The packing units are preferably produced by squeezing the various pieces from a bar of the material to be processed, particularly a lead bar. The diameter of the circular cylindrical bar of the starting material, e.g., lead, is preferably between 5 and 25 mm.

The invention will now be described with reference to the accompanying drawing, in which FIGS. 1, and 2 are views of leaden packing units embodying the principles of the invention.

The packings are formed from sections of rods or colums and consist preferably of lead. The lead rods are squeezed off into short sections. During the squeezing 01f operation the lead will be deformed to produce the parallel edges 5 and 6 for each section squeezing off. As shown in FIG. 1 a pillow-shaped form will be produced having curved outer surfaces, four corners 1, 2, 3 and 4, and two sharp edges 5 and 6. FIG. 2 shows the tetrahedral form, in which 7 and 8 are sharp edges arranged at to each other, and edges 9, 10, 11 and 12 are rounded. Other packing units in accordance with the present invention may be squeezed off by suitable compression cuts turned alternately by 90".

We claim:

Process for the production of packing units having substantially convex limiting surfaces and tetrahedral form for regenerators operating at temperatures between the liquefaction temperatures of nitrogen and hydrogen, which comprises squeezing oif said packing units as sections from a cylindrical bar of lead as starting material by successive compression cuts the second being taken 90 with respect to the first but spaced along the bar axially, thereby forming said sections of tetrahedral form with substantially convex limiting surfaces being turned toward each other alternately by 90 References Cited in the file of this patent UNITED STATES PATENTS Re. 22,696 Frischer Nov. 27, 1945 409,747 Hasting Aug. 27, 1889 628,541 Kester July 11, 1899 1,997,871 Miller et al Apr. 16, 1935 2,299,143 Hellwig Oct. 20, 1942 2,413,179 Grandmont et al Dec. 24, 1946 2,539,372 vMetzler Jan. 23, 1951 2,624,556 Kistler Ian. 6, 1953 2,631,921 ODe'll Mar. 17, 1953 2,712,169 Buttress July 5, 1955 2,760,259 Troendly Aug. 28, 1956 3,015,153 Liebe Jan. 2, 1962 3,062,509 Muller Nov. 6, 1962 FOREIGN PATENTS 360,507 Great Britain Nov. 12, 1931 420,906 Italy May 9, 1947 459,544 Germany May 4, 1928 591,820 Germany Jan. 27, 1934 711,684 Great Britain July 7, 1954 OTHER REFERENCES Metal work, Technology and Practice, 0. A. Ludwig, McKnight & McKnight, Bloomington, Illinois, 1943,

pages 285-6. Copy in Group 330. 

